Macrowine 2021
IVES 9 IVES Conference Series 9 How pressing techniques affect must composition and wine quality of Pinot blanc

How pressing techniques affect must composition and wine quality of Pinot blanc


This study investigates how the sensory profile of Pinot Blanc is affected from different maceration and pressing techniques. Grapes were sourced from four vineyards in the village Tramin in South Tyrol. For the experiment 200 kg of grapes from each vineyard site were hand picked the day before harvest for the commercial winery took place. Grapes were stored over night at 4°C, homogenized and processed in the experimental winery at Laimburg research centre the day after harvest. Four different pressing techniques were applied in duplicates of 100kg each. Treatments were composed as follows: (1) “classic”, pre-installed press program with 120 minutes and crumbling after each pressure step, (2) “cremant”, gentle and sequential press program with 180 minutes and fewer crumbling steps (3) “maceration” consisted of a 120 minutes cold soak followed by a very quick press program of 30 minutes and (4) “long pressing” consisted of a two hours maceration during the press program once the free run juice was drained. To track the evolution and extraction kinetics of pH, total acidity, tartaric acid, malic acid, total polyphenols and catechins, juice samples were taken after each cycle and analyzed right away in the laboratory. At approximately 150 kPa pressure the must is divided in fraction one and fraction two what corresponds to the press-wine. Two experimental wines are made out of each batch of grapes: one contains only must from the first fraction, and the other is a combination of fraction one and two in the original proportion. Sensory evaluation took place 6 and 18 months after harvest. Chemical must composition depends on the processing technique in the winery. Total acidity, pH, malic acid and polyphenol content of the must are affected from the chosen press program. Nonetheless the absolute content of the chemical components is different for the different pressing techniques; the trend of the extraction of these must components remains more or less the same during the pressing procedure. An exception was potassium, which showed a different behaviour in the “cremant” press-program. The different pressing techniques had an impact on the sensory profile of the wines. In the aroma profile, wines from the maceration treatment were marked best; whereas for the mouth-feel parameters the control wines achieved slightly better marks. Wines pressed with the “cremant” program were described as less complex, thinner and more acidity driven. Wines from treatment “long pressing” were reductive, less fruity ending up with a low overall quality. Two hours maceration followed by quick pressing showed interesting results. This might be a promising option to save press-capacity and to process more fruit in the short period of harvest. Further, for overall wine quality it was beneficial to use the entire must; wines made without the press-fraction are described as too light, not as complex and not as typical.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster


Konrad Pixner*


Contact the author


IVES Conference Series | Macrowine | Macrowine 2016


Related articles…

The role of tomato juice serum in malolactic fermentation in wine

Introduction: Malolactic fermentation (MLF) is a common process in winemaking to reduce wine acidity, maintain microbial stability and modify wine aroma. However, successful MLF is often hampered by their sluggish or stuck activity of malolactic bacteria (MLB) which may be caused by nutrient deficiency, especially when MLB are inoculated after alcoholic fermentation (Alexandre et al., 2004; Lerm et al., 2010). Identification and characterization of essential nutrients and growth factors for MLB allows for production of highly efficient nutrient supplements for MLF.

Partial dealcoholisation of red wine by reverse osmosis-evaporative perstraction: impact on wine composition

Around the world, the alcohol content of wine has been steadily increasing; partly as a consequence of climate change, but also due to improvements in viticultural management practices and winemaking techniques [1,2]. Concurrently, market demand for wines with lower alcohol levels has increased as consumers seek to reduce alcohol intake for social and/or health reasons [3]. As such, there is increasing demand for both innovative methods that allow winemakers to produce ‘reduced alcohol wines’ (RAW) and a better understanding of the impact of such methods on the composition of RAW. This study therefore aimed to investigate compositional changes in two red wines resulting from partial alcohol removal following treatment by one such method, involving a combination of reverse osmosis and evaporative perstraction (RO-EP).

Pesticide removal in wine with a physical treatment by molecular sieving

All along the winemaking process, conditioning and aging, wine is susceptible to be contaminated by different molecules. Contaminations can have various origins, related to wine microorganisms or as a result of an exogenous contamination. The aforementioned contamination of the wine can be caused by the migration of molecules from the materials in contact with the wine or by a contamination from exogenous molecules present in the air. Regardless of the source of the contamination, mainly two types of consequences can be observed.

Extraction of polyphenols from grape marc by supercritical fluid extraction (SFE) and evaluation of their ‘bioavailability’ as dietary supplements

In the winemaking process, several compounds that remain in the grape skins and seeds after the fermentation stage are bioactive-compounds (substances with potential beneficial effects on health) that can be extracted in order to recovery valuable substances with a high commercial value for the cosmetic, food (nutraceuticals) and pharmaceutical industries. The skins contain significant amounts of bioactive substances such as tannins (16-27%) and other polyphenolic compounds (2-6.5%) in particular, catechins, anthocyanins, proanthocyanins, quercetin , ellagic acid and resveratrol.

Fractionation of copper and iron in wine: Assessment of potential macromolecule and sulfur binding agents

Copper and iron are known to substantially impact wine stability through oxidative, reductive or colloidal phenomena. However, the binding of metal ions to different wine components under wine conditions, and the impact of this binding on the ability of the metal ions to induce spoilage processes, is not well understood. This study surveyed a range of red and white wines for an understanding of the variability of broad metal categories within the wines. The techniques utilized included an electrochemical constant current stripping potentiometry technique (ccSP), and solid phase extraction (SPE) fractionation of wine with subsequent analysis of the metal content of each fraction by inductively coupled plasma – optical emission spectroscopy (ICP-OES).